Generally, a preset tour camera is unmanned surveillance equipment that continuously takes images of a plurality of predetermined classification groups having different surveillance distances and angles, through predefined movement and stop operations.
In other words, because the preset tour camera enables simultaneously monitoring multiple classification groups by taking images thereof through a single image obtaining device, the number of image obtaining devices may be reduced, thus reducing installation and management cost.
As such a preset tour camera, a pan-tilt-zoom camera is widely used because a pan-tilt-camera typically has a panning function capable of horizontal rotation, a tilting function capable of vertical rotation, and a zooming function capable of changing a focal distance.
Here, the multiple image frames obtained in real-time by the preset tour camera are continuously stored in a storage medium indiscriminately rather than by being classified according to the classification groups. Namely, the multiple image frames are not classified by the classification groups, and stored as a form of one motion picture.
Therefore, when an accident occurs at a certain place among a plurality of surveillance places, all the image frames stored in the storage medium are sequentially searched and analyzed, thus much time and effort are required for the image analysis and it is difficult to promptly handle the accident.
To solve the above-mentioned problem, it is necessary to research a technique in which image frames for multiple classification groups, obtained by the preset tour camera, may be classified and stored by the classification groups.